题解 | #统计一句话中重复单词的个数#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String line = scanner.nextLine();
        Map<Character, Integer> map = new LinkedHashMap<Character, Integer>();

        //write your code here......
        for (char ch : line.toCharArray()) {
            // 判断是否是字母
            if (Character.isLetter(ch)) {
                // map.put(ch, map.getOrDefault(ch,0)+1); // 方法一

//                if (map.containsKey(ch)) { // 方法二
//                    map.compute(ch, (key,value) -> value+1);
//                } else {
//                    map.put(ch,1);
//                }

                map.merge(ch, 1, (oldValue, newValue) -> oldValue+newValue); // 方法三
            }

        }

        Set<Map.Entry<Character, Integer>> entrys = map.entrySet();
        for (Map.Entry<Character, Integer> entry : entrys) {
            System.out.println(entry.getKey() + ":" + entry.getValue());
        }
    }
}